Access to internal and external structures of the heart may be desirable for the treatment of cardiovascular disease. In some cases, the treatment may involve the delivery of devices to the heart. One way in which a heart may be accessed for device delivery is by an intravascular approach. Intravascular pathways to the heart may involve advancing the device from a femoral vein to the vena cava, through which the chambers and valves of the right side of the heart (e.g., right atrium, right ventricle, etc.) may be accessed. The left side of the heart may also be accessed from this approach by using a transseptal procedure. Alternatively, the left atrium and left ventricle may be intravascularly accessed by a retrograde pathway from the aorta.
However, intravascular access to the heart may not be ideal in all circumstances, such as for the delivery of larger devices, and especially if external structures of the heart are targeted. In such circumstances, the heart may also be accessed through an opening or puncture in the pericardium, which may provide direct access to the external (epicardial) surface of the heart. Accessing the heart via a non-effused pericardium is becoming a recognized access route to the heart. The ability to access the heart via a non-vascular pathway may be useful for a variety of applications, including device or drug delivery, left atrial appendage exclusion, ablation of fibrillating tissue, placement of leads, and the like. Despite these benefits, puncturing the pericardium without contacting and/or damaging the heart itself may prove to be a challenge. Current methods that attempt to reduce this risk involve grasping and/or suctioning the pericardium prior to puncturing it, but the presence of epicardial fat and other irregularities may prevent direct access to the pericardium. In some cases, highly trained physicians may be able to pierce the pericardium without piercing the heart by carefully advancing a needle towards the heart. They may rely on tactile feedback to avoid puncturing the heart, and use this tactile feedback to accommodate and/or compensate for the displacement of the heart and pericardium during a beating heart procedure. However, advancing conventional needles to the heart by tactile feedback may be particularly risky for inexperienced physicians, as these conventional needles may be accidentally advanced into the heart. Additional methods and devices for accessing the pericardial space are desirable.